Process for synthesis of polymer compositions with reduced halogen content, polymer composition with reduced halogen content as well as use of this composition

ABSTRACT

The present invention relates to processes for synthesis of polymer compositions with reduced living halogen content, wherein ethylenically unsaturated monomers are polymerized by means of initiators containing a transferable halogen and of one or more catalysts comprising at least one transition metal in the presence of ligands which can form a coordination compound with the metal catalyst or catalysts and, after the polymerization, the living halogen atoms present in the polymer are at least partly eliminated, wherein after the polymerization the polymer composition is reacted with at least one organic nitrogen compound in the presence of a nonpolar solvent.  
     Furthermore, polymer compositions with reduced living halogen content as well as the use of these compositions as additive to lubricating oils is subject matter of the present invention.

[0001] Process for synthesis of polymer compositions with reducedhalogen content, polymer composition with reduced halogen content aswell as use of this composition invention relates to a process forsynthesis of polymer compositions with reduced living halogen content,wherein ethylenically unsaturated monomers are first polymerized bymeans of initiators containing a transferable halogen and of one or morecatalysts comprising at least one transition metal in the presence ofligands which can form a coordination compound with the metal catalystor catalysts. The invention also relates to polymer compositions withreduced living halogen content as well as to the use of these polymercompositions.

[0002] Radical polymerization is an important commercial process forsynthesis of diverse polymers, such as PMMA and polystyrene. It suffersfrom the disadvantage that it is relatively difficult to control thecomposition of the polymers, the molecular weight and the molecularweight distribution.

[0003] One solution to this problem is offered by the so-called ATRPprocess (=Atom Transfer Radical Polymerization). It is assumed that thisprocess comprises “living” radical polymerization, although thedescription of the mechanism is not to be construed as limitative. Inthis process a transition metal compound is reacted with a compoundcontaining a transferable group of atoms. Under these conditions thetransferable group of atoms is transferred to the transition metalcompound, whereby the metal is oxidized. A radical that adds ontoethylenic groups is formed in this reaction. The transfer of the groupof atoms to the transition metal compound is reversible, however, and sothe group of atoms is transferred back to the growing polymer chain,whereby a controlled polymerization system is formed. Accordingly it ispossible to control the composition of the polymer, the molecular weightand the molecular weight distribution.

[0004] This reaction procedure is described, for example, by J- S. Wanget al., J. Am. Chem. Soc., Vol. 117, pp. 5614-5615, and byMatyjaszewski, Macromolecules, Vol. 28, pp. 7901-7910 (1995).Furthermore, International Patent Applications WO 96/30421, WO 97/47661,WO 97/18247, WO 98/40415 and WO 99/10387 disclose modifications of theaforesaid ATRP.

[0005] The mechanism described hereinabove is not undisputed. WO97/47661, for example, states that polymerization takes place byinsertion, and not by a radical mechanism. Such a differentiation is notpertinent to the present invention, however, since in the reactionprocedure disclosed in WO 97/47661 there are used compounds which arealso employed for ATRP.

[0006] The advantages of known ATRP polymerization processes, however,are largely limited to monomers which are themselves polar or which arereadily soluble in polar media. Certainly the occasional use of nonpolaraprotic hydrocarbons such as benzene, toluene, xylene cyclohexane andhexane is also known from the literature, but the polymers synthesizedwith these solvents exhibit much greater polydispersity. This effect isdescribed in, for example, WO 98/40415.

[0007] Usually the polymers obtainable by ATRP processes contain halogenatoms, which as the living chain end permit a narrow molecular weightdistribution. Nevertheless, these halogens, which usually arenecessarily present at the chain end, are associated with disadvantages.For example, these halogen constituents can be liberated duringdecomposition of the polymers. Especially upon contact with metals suchas are contained in pumps, motors and similar components, liberatedhalogens cause corrosion, which leads to destruction of the pumps,motors, etc. Furthermore, the halogens lead to problems in reprocessingof the polymers. In particular, combustion can lead to highly toxicdioxins.

[0008] The associated problems as well as a process for removal ofhalogens from polymers obtained by ATRP processes are described in, forexample, International Patent Application WO 99/54365. This documentdescribes a process in which the living halogens are transformed todouble bonds, by reacting the ATRP polymer containing a halogen atom asthe active chain end subsequent to polymerization with a compoundcontaining a double bond capable of limited ATRP polymerization. Thecompound containing the double bond capable of limited polymerization isadded to the living end of the ATRP polymer, and the living halogen atomis eliminated with formation of a double bond. 1,1-Dimethylethylene,1,1-diphenylethylene, vinyl acetate, isoprenyl acetate, α-methylstyrene,1,1-dialkoxyolefin, dimethyl itaconate and diiusobutene are explicitlydisclosed therein as compounds containing the double bond capable oflimited polymerization.

[0009] In nonpolar solvents such as mineral oils, however, the use ofthis process does not lead to the desired elimination of the livinghalogen atom at the active chain end and to the formation of theterminal double bond. Instead, the living halogen remains unchanged inthe polymer.

[0010] Nevertheless, processes which can be carried out in nonpolarsolvents in order to synthesize ATRP polymer compositions with reducedliving halogen content at the active chain end are needed by industry.Such processes would be universally advantageous, especially forsynthesis of polymer products such as mineral-oil additives for use innonpolar solvents, because the otherwise necessary step for changingsolvents is obviated. Instead, the desired compositions could besynthesized directly.

[0011] The paper by M. Bednarek, T. Biedroni and P. Kubisa entitled“Synthesis of block copolymers by atom transfer radical polymerizationof tert-butyl acrylate with poly(oxyethylene) macroinitiators”,Macromol. Rapid Commun., 20, 59-65 (1999), describes the ATRP bulkpolymerization of tert-butyl acrylate using a polyoxyethylenemacroinitiator. CuBr is used as catalyst andpentamethyldiethylenetriamine (PMDETA) as the ligand. During thispolymerization, the living halogen at the active chain end is replacedby hydrogen in a side reaction. In this connection, the authors (page65, 1st paragraph) do not rule out participation of the PMDETA in theexchange reaction. A process for selective removal of the living halogenat the active chain end of the ATRP polymer and for formation of apolymer with a terminal double bond is not disclosed by this paper.

[0012] In view of the prior art, it was now an object of the presentinvention to provide processes for synthesis of polymer compositionswith reduced halogen content, wherein the living halogen atom at theactive chain end should be substantially removed.

[0013] A further object was to provide a process that can be performedinexpensively and applied on a large industrial scale. Furthermore, theprocess should be possible easily and simply with commercially availablecomponents.

[0014] Furthermore, broadening of the molecular-weight distribution ofthe polymer composition should be prevented by the reaction.

[0015] A further object of the present invention was to provide, forsynthesis of polymer compositions with reduced halogen content, aprocess in which decomposition of the polymers contained in thecomposition is prevented.

[0016] A further object was to find polymer compositions which have anexcellent spectrum of properties, so that they can be added as an idealadditive to lubricating oils.

[0017] This means among other requirements that the polymers containedin the composition have low sensitivity to oxidation and high resistanceto shear loads.

[0018] In particular, the polymers contained in the polymer compositionmust have a narrow molecular-weight distribution and be substantiallyhalogen-free.

[0019] These objects are achieved by a process for synthesis of apolymer composition having all features of claim 1, as are other objectswhich are not explicitly cited but which can be obviously derived orinferred from the relationships discussed herein in the introduction.Advantageous modifications of the inventive process are protected in thedependent claims which refer back to claim 1. As regards the polymercompositions, the independent product claim provides a solution to theunderlying problem, while the claim from the use category protects apreferred use of a polymer solution synthesized according to the presentprocess.

[0020] By the fact that, after polymerization, the polymer compositionis reacted with at least one organic nitrogen compound in the presenceof a nonpolar solvent, it has become possible in a way that is notdirectly foreseeable to provide, for synthesis of a polymer composition,a process with which the living halogen content of the polymer can bereduced directly in a nonpolar solvent.

[0021] For this purpose ethylenically unsaturated monomers arepolymerized by means of initiators containing a transferable halogen andof one or more catalysts comprising at least one transition metal in thepresence of ligands which can form a coordination compound with themetal catalyst or catalysts. This type of synthesis can be achievedparticularly inexpensively and in this regard is of industrial interest.

[0022] At the same time, several other advantages can be achieved by theinventive process. They include among others:

[0023] A narrow distribution of the polymers in the polymer compositionssynthesized by the process.

[0024] The inventive process permits excellent control of the molecularweight of the polymers contained in the compositions.

[0025] The polymerization can be performed with relatively few problemsas regards pressure, temperature and solvent, acceptable results beingobtained under certain circumstances even at moderate temperatures.

[0026] The inventive process has very few side reactions.

[0027] The process can be performed inexpensively.

[0028] The polymer is decomposed not at all or only slightly by theprocess.

[0029] High yields can be achieved by means of the inventive process.

[0030] Substantially double bonds are formed by the reaction with theorganic nitrogen compound. These can be used if necessary for furtherreactions analogous to those of polymers.

[0031] Polymers with a predetermined composition and tailor-madestructure can be synthesized by means of the process of the presentinvention.

[0032] The polymer compositions obtainable by the process of the presentinvention are relatively stable to oxidative decomposition and to shearloading.

[0033] The halogen-reducing reaction of the polymers obtained by theATRP processes with an organic nitrogen compound takes place in thepresence of a nonpolar solvent.

[0034] This includes hydrocarbon solvents, examples being aromaticsolvents such as toluene, benzene and xylene, and saturated hydrocarbonssuch as cyclohexane, heptane, octane, nonane, decane, dodecane, whichmay also be used in branched form. These solvents can be usedindividually and also as a mixture. Particularly preferred solvents aremineral oils and synthetic oils as well as mixtures thereof. Of these,mineral oils are most particularly preferred.

[0035] Mineral oils are known in themselves and are commerciallyavailable. They are generally obtained from petroleum or crude oil bydistillation and/or refining and if necessary further purification andconversion processes. In this connection the term mineral oil applies inparticular to the higher-boiling fractions of crude oil or petroleum. Ingeneral, the boiling point of mineral oil is higher than 200° C.,preferably higher than 300° C. at 5000 Pa. Synthesis by low-temperaturecarbonization of shale oil, coking of bituminous coal, distillation oflignite with exclusion of air as well as hydrogenation of bituminouscoal or lignite is also possible. A small proportion of mineral oils isalso obtained from raw materials originating from plants (such asjojoba, rape) or animals (such as neatsfoot oil). Accordingly, mineraloils contain various proportions of aromatic, cyclic, branched andstraight-chain hydrocarbons, depending on origin.

[0036] In general, a distinction is made between paraffin-base,naphthenic and aromatic fractions in crude oils or mineral oils. In thisconnection the term paraffin-base fraction stands for relativelylong-chain or highly branched isoalkanes, and naphthenic fraction standsfor cycloalkanes. Furthermore, depending on their origin and conversionprocess, mineral oils contain different proportions of n-alkanes,isoalkanes with low degree of branching, so-called monomethyl-branchedparaffins, and compounds with heteroatoms, especially O, N and/or S,with which there are associated polar properties. The proportion ofn-alkanes in preferred mineral oils is less than 3 wt %, the proportionof the compounds containing O, N and/or S is less than 6 wt %. Theproportion of aromatics and of monomethyl-branched paraffins isgenerally in the range of 0 to 30 wt % each. According to oneinteresting aspect, mineral oil comprises mainly naphthenic andparaffin-base alkanes, which in general contain more than 13, preferablymore than 18 and most particularly preferably more than 20 carbon atoms.The proportion of these compounds is generally ≧60 wt %, preferably ≧80wt %, but these values are not to be construed as limitative. Ananalysis of especially preferred mineral oils performed usingconventional techniques such as urea separation and liquidchromatography on silica gel reveals, for example, the followingconstituents. In this connection, the percentage values refer to thetotal weight of the particular mineral oil being used:

[0037] n-alkanes with about 18 to 31 C atoms:

[0038] 0.7 to 1.0%,

[0039] slightly branched alkanes with 18 to 31 C atoms:

[0040] 1.0 to 8.0%,

[0041] aromatics with 14 to 32 C atoms:

[0042] 0.4 to 10.7%,

[0043] isoalkanes and cycloalkanes with 20 to 32 C atoms:

[0044] 60.7 to 82.4%,

[0045] polar compounds:

[0046] 0.1 to 0.8%

[0047] loss:

[0048] 6.9 to 19.4%.

[0049] Valuable information on analysis of mineral oils as well as alisting of mineral oils having different composition can be found in,for example, Ullmanns Encyclopedia of Industrial Chemistry, 5th Editionon CD-ROM, 1997, key word “lubricants and related products”.

[0050] Synthetic oils include among other compounds organic esters,organic ethers such as silicone oils, and synthetic hydrocarbons,especially polyolefins. They are usually somewhat more expensive thanmineral oils, but have advantages in terms of performance. Furtherelucidation can be found in the 5 API categories of base-oil types (API:American Petroleum Institute). In this connection these base oils can beused particularly preferably as solvents. These solvents are used beforeor during the reaction to reduce the halogen content of the polymers,preferably in a proportion of 1 to 99 wt %, especially preferably 5 to95 wt % and most particularly preferably 10 to 60 wt % relative to thetotal weight of the mixture. During the reaction with an organicnitrogen compound, the composition may also contain polar solvents, butthe proportion thereof is limited by the fact that these solvents mustnot exert any unacceptably detrimental effect on the halogen-reducingreaction.

[0051] According to the invention, the living halogens present as activecenters in the polymer are at least partly eliminated. In thisconnection the term “living halogens” denotes the halogens bound to thereactive centers at the chain ends. The reactive centers remain intacteven after complete “living” radical polymerization (ATRP) of theinitially used monomers, and thus permit the addition of furthermonomers. Preferably each polymer contains one living halogen at first,although more than one living halogen per polymer chain is alsoconceivable. The active chain end containing the living halogen ispreferably transformed to a double bond by the elimination.

[0052] In the scope of the present invention, an organic nitrogencompound is used for reduction of the living halogen content of thepolymer. Organic nitrogen compounds are known in themselves. Besides oneor more nitrogen atoms, they contain alkyl, cycloalkyl or aryl groups,and the nitrogen atom may also be a member of a cyclic group.

[0053] Organic nitrogen compounds that can bind metal atoms or functionas ligands are preferred. Such compounds are described as ligands laterin the text. These organic nitrogen compounds usable as ligands aredescribed in International Patent Applications WO 97/18247, WO 98/40415and WO 97/47661 among other documents.

[0054] They include, among others, heterocyclic aromatic nitrogencompounds. These are aromatic compounds which contain cyclic groups with4 to 12 carbon atoms and in which one or more CH groups of the aromaticrings are replaced by nitrogen atoms.

[0055] They include in particular compounds which contain one or morepyrrole, imadizole, indole, quinoline, isoquinoline, pyrimidine orpyridine groups. Examples of such compounds are 2,2-bipyridine,alkyl-2,2-bipyridine, such as 4,4-di-(5-nonyl)-2,2-bipyridine,4,4-di-(5-heptyl)-2,2-bipyridine.

[0056] Organic nitrogen groups containing aliphatic groups are alsopreferred. These are compounds which contain saturated or unsaturatedalkyl groups or cycloalkyl groups in addition to the nitrogen atom.

[0057] Many of these organic nitrogen compounds can be represented ingeneral by the formula R³¹-Z-(R³³-Z)_(m)-R³², wherein R³¹ and R³²independently denote H, C₁, to C₂₀ alkyl, aryl or heterocyclyl, whichmay or may not be substituted, and m denotes an integral number rangingfrom 0 to 10, preferably 1 to 3. These substituents include alkoxygroups and the alkylamino groups among others. R³¹ and R³² may form asaturated, unsaturated or heterocyclic ring as the case may be.Particularly preferably R³¹ and R³² represent hydrogen, methyl, ethyland propyl, methyl being preferred among those. Z denotes NH or NR³⁴,wherein R³⁴ has the same meaning as R³¹. Particularly preferably R³⁴represents hydrogen, methyl, ethyl and propyl, methyl being preferredamong those. R³³ independently denotes a divalent group with 1 to 40 Catoms, preferably 2 to 4 C atoms, which may be straight-chain, branchedor cyclic, such as a methylene, ethylene, propylene, butylene orcyclohexylene group.

[0058] Alkyl groups are saturated or unsaturated, branched orstraight-chain hydrocarbon groups with 1 to 40 carbon atoms, such asmethyl, ethyl, propyl, butyl, pentyl, 2-methylbutyl, pentenyl,cyclohexyl, heptyl, 2-methylheptenyl, 3-methylheptyl, octyl, nonyl,3-ethylnonyl, decyl, undecyl, 4-propenylundecyl, dodecyl, tridecyl,tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl,eicosyl, cetyleicosyl, docosyl and/or eicosyltetratriacontyl.

[0059] Aryl groups are cyclic aromatic groups having 6 to 14 carbonatoms in the aromatic ring. These groups may be substituted. Examples ofsubstituents are straight-chain and branched alkyl groups with 1 to 6carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl,2-methylbutyl or hexyl; cycloalkyl groups such as cyclopentyl andcyclohexyl; aromatic groups such as phenyl or naphthyl; amino groups,ether groups, ester groups as well as halides.

[0060] Heterocyclyl groups are cyclic groups with 4 to 12 carbon atoms,in which one or more of the CH₂ groups of the ring is or are replaced byheteroatom-containing groups, such as O, S, NH and/or NR, wherein thegroup R has the same meaning as R³¹.

[0061] Preferred aliphatic nitrogen compounds aretris(2-aminoethyl)amine (TREN), tributylamine,N,N-diphenyl-1,4-phenylenediamine, C₁₃H₂₇—NH₂,N,N,N′,N′,N″-pentamethyldiethylenetriamine (PMDETA),1,1,4,7,10,10-hexamethyltriethylenetetramine and/ortetramethylethylenediamine (TMEDA), diethylenetriamine (DETA).

[0062] Furthermore, organic nitrogen compounds in which at least onemethyl group is bound to the nitrogen atom are particularly preferred,such as hexamethyltriethylenetetramine, PMDETA or TMEDA.

[0063] These compounds can be used individually or as mixtures. Theproportion depends on the living halogen content of the composition.Preferably the molar ratio of organic nitrogen compound to livinghalogen is 0.5:1 to 10:1, expediently 0.5:1 to 4:1, especially 1.25:1 to4:1.

[0064] It was particularly surprising that a reduction of the livinghalogen content can be achieved by means of organic nitrogen compoundsthat can be used as ligands during the polymerization, even though thisexchange leads to a termination reaction. Accordingly, the proportion ofthe organic nitrogen compounds is preferably increased to the valuesindicated in the foregoing after completion of the polymerization.

[0065] It is assumed that metal-containing catalysts as well as ligands,which preferably contain nitrogen, must also be present during thereaction.

[0066] In a particularly surprising result, however, it was found thatthe conversion of the reaction that leads to reduction of the livinghalogen content of the polymer can be increased when the organicnitrogen preferably used as the ligand is present in excess relative tothe metal, although this requirement is not to be construed aslimitative.

[0067] The reaction of the polymer containing the living halogen withthe organic nitrogen compound can be performed at normal pressure,reduced pressure or above-atmospheric pressure. The reaction temperaturealso is not critical. In general, however, it ranges from −20° C. to200° C., preferably 20° C. to 200° C., and particularly preferably 90°C. to 150° C., although these values are not to be construed aslimitative. The duration of the reaction depends on the parametersdescribed in the foregoing. Usually a large decrease of the livinghalogen content is already found after one hour, although this value isnot to be construed as limitative. If the most complete possibleexchange is to be achieved, a relatively long reaction duration, whichmay range from 2 to 48 hours, will be necessary in some cases.

[0068] It is characteristic of the reaction according to the presentinvention that the living halogen atoms contained in the polymer areeliminated at least partly hereby. This observation is true for theliving halogen content of the polymers, or in other words the content ofliving halogen before and after the reaction, in which connection theterm partly can mean a reduction of the content by, for example, 5 wt %,in each case relative to the starting content of living halogens.

[0069] In preferred embodiments of the inventive process, the reductionof the living halogen content is much larger, and so the living halogencontent is preferably reduced to 60 wt %, particularly preferably to 30wt % and most particularly preferably 5 wt %, in each case relative tothe starting content of living halogens, although these values are notto be construed as limitative.

[0070] Polymers obtainable preferably by the process of the presentinvention preferably have a living halogen content of smaller than orequal to 1000 ppm, expediently smaller than or equal to 600 ppm,especially smaller than or equal to 200 ppm and particularly preferablysmaller than or equal to 100 ppm, relative to the total weight of thecomposition.

[0071] In the present invention, any monomer capable of radicalpolymerization can be used as the monomer. Especially suitable asmonomers for polymerization according to the present invention, however,are compounds corresponding to the formula:

[0072] wherein R^(1*) and R^(2*) are selected independently from thegroup comprising hydrogen, halogens, CN, straight-chain or branchedalkyl groups with 1 to 20, preferably 1 to 6 and especially preferably 1to 4 carbon atoms, which may be substituted with 1 to (2n+1) halogenatoms, wherein n is the number of carbon atoms of the alkyl group (forexample, CF₃), α,β-unsaturated straight-chain or branched alkenyl oralkynyl groups with 2 to 10, preferably 2 to 6 and especially preferably2 to 4 carbon atoms, which may be substituted with 1 to (2n−1) halogenatoms, preferably chlorine, wherein n is the number of carbon atoms ofthe alkyl group, for example CH₂═CCl—, cycloalkyl groups with 3 to 8carbon atoms, which may be substituted with 1 to (2n−1) halogen atoms,preferably chlorine, wherein n is the number of carbon atoms of thecycloalkyl group; C(═Y*)R^(5*), C(═Y*)NR^(6*)R^(7*), Y*C(═Y*)R^(5*),SOR^(5*), SO₂R^(5*), OSO₂R^(5*), NR^(8*)SO₂R^(5*), PR^(5*) ₂,P(═Y)R^(5*) ₂, Y*PR^(5*) ₂, Y*P(═Y*)R^(5*) ₂, NR^(8*) ₂ which can bequaternized with an additional R^(8*), aryl or heterocyclyl group,wherein Y* can be NR^(8*), S or O, preferably O; R^(5*) is an alkylgroup with 1 to 20 carbon atoms, an alkylthio group with 1 to 20 carbonatoms, OR¹⁵ (R¹⁵ is hydrogen or an alkali metal), an alkoxy group with 1to 20 carbon atoms, an aryloxy or heterocyclyloxy group; R^(6*) andR^(7*) independently are hydrogen or an alkyl group with 1 to 20 carbonatoms, or R^(6*) and R^(7*) together can form an alkylene group with 2to 7, preferably 2 to 5 carbon atoms, wherein they form a 3-membered to8-membered ring, preferably a 3-membered to 6-membered ring, and R^(8*)is hydrogen, a straight-chain or branched alkyl group or aryl group with1 to 20 carbon atoms; R^(3*) and R^(4*) are independently selected fromthe group comprising hydrogen, halogen (preferably fluorine orchlorine), alkyl groups with 1 to 6 carbon atoms and COOR^(9*), whereinR^(9*) is hydrogen, an alkali metal or an alkyl group with 1 to 40carbon atoms, or R^(1*) and R^(3*) together can form a group of formula(CH₂)_(n′), which may be substituted with 1 to 2n′ halogen atoms or C₁to C₄ alkyl groups, or can form the formula C(═O)—Y*—C(═O), wherein n′is from 2 to 6, preferably 3 or 4 and Y* is as defined hereinabove; andwherein at least 2 of the groups R^(1*), R^(2*), R^(3*) and R^(4*) arehydrogen or halogen.

[0073] These monomers include among others

[0074] vinyl halides, such as vinyl chloride, vinyl fluoride,

[0075] vinylidene chloride and vinylidene fluoride;

[0076] vinyl esters, such as vinyl acetate;

[0077] styrene, substituted styrenes with an alkyl substituent in theside chain, such as α-methylstyrene and α-ethylstyrene, substitutedstyrenes with an alkyl substituent on the ring, such as vinyltoluene andp-methylstyrene, halogenated styrenes such as monochlorostyrenes,dichlorostyrenes, tribromostyrenes and tetrabromostyrenes;

[0078] heterocyclic vinyl compounds, such as 2-vinylpyridine,3-vinylpyridine, 2-methyl-5-vinylpyridine, 3-ethyl-4-vinylpyridine,2,3-dimethyl-5-vinylpyridine, vinylpyrimidine, vinylpiperidine,9-vinylcarbazole, 3-vinylcarbazole, 4-vinylcarbazole, 1-vinylimidazole,2-methyl-1-vinylimidazole, N-vinylpyrrolidone, 2-vinylpyrrolidone,N-vinylpyrrolidine, 3-vinylpyrrolidine, N-vinylcaprolactam,N-vinylbutyrolactam, vinyloxolane, vinylfuran, vinylthiophene,vinylthiolane, vinylthiazoles and hydrogenated vinylthiazoles,vinyloxazoles and hydrogenated vinyloxazoles;

[0079] vinyl and isoprenyl ethers;

[0080] maleic acid derivatives, such as maleic anhydride,

[0081] methylmaleic anhydride, maleimide, methylmaleimide;

[0082] dienes such as divinylbenzene; and (meth)acrylates.

[0083] Preferred monomers are (meth)acrylates. The expression(meth)acrylates includes methacrylates and acrylates as well as mixturesof the two. These monomers are widely known. They include among others

[0084] (meth)acrylates derived from saturated alcohols, such as methyl(meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl(meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate,2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, 2-tert-butylheptyl(meth)acrylate, octyl (meth)acrylate, 3-iso-propylheptyl (meth)acrylate,nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate,5-methylundecyl (meth)acrylate, dodecyl (meth)acrylate, 2-methyldodecyl(meth)acrylate, tridecyl (meth)acrylate, 5-methyltridecyl(meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate,hexadecyl (meth)acrylate, 2-methylhexadecyl (meth)acrylate, heptadecyl(meth)acrylate, 5-isopropylheptadecyl (meth)acrylate,4-tert-butyloctadecyl (meth)acrylate, 5-ethyloctadecyl (meth)acrylate,3-isopropyloctadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl(meth)acrylate, eicosyl (meth)acrylate, cetyleicosyl (meth)acrylate,stearyleicosyl (meth)acrylate, docosyl (meth)acrylate and/oreicosyltetratriacontyl (meth)acrylate;

[0085] (meth)acrylates derived from unsaturated alcohols, such as oleyl(meth)acrylate, 2-propynyl (meth)acrylate, allyl (meth)acrylate, vinyl(meth)acrylate, etc.;

[0086] amides and nitriles of (meth)acrylic acid, such asN-(3-dimethylaminopropyl) (meth)acrylamide, N-(diethylphosphono)(meth)acrylamide, 1-(meth)acryloylamido-2-methyl-2-propanol,N-(3-dibutylaminopropyl) (meth)acrylamide,N-t-butyl-N-(diethylphosphono) (meth)acrylamide,N,N-bis(diethylaminoethyl) (meth)acrylamide,4-methacryloylamido-4-methyl-2-pentanol, methacryloylamidoacetonitrile,N-(methoxymethyl) (meth)acrylamide, N-(2-hydroxyethyl) (meth)acrylamide,N-(dimethylaminoethyl) (meth)acrylamide, N-methyl-N-phenyl(meth)acrylamide, N,N-diethyl (meth)acrylamide, N-acetyl(meth)acrylamide, N-methyl (meth)acrylamide, N-N-dimethyl(meth)acrylamide, N-isopropyl (meth)acrylamide;

[0087] aminoalkyl (meth)acrylates, such astris(2-(meth)acryloxyethyl)amine, N-methylformamidoethyl (meth)acrylate,3-diethylaminopropyl (meth)acrylate, 4-dipropylaminobutyl(meth)acrylate, 2-ureidoethyl (meth)acrylate;

[0088] other nitrogen-containing (meth)acrylates, such asN-((meth)acryloyloxyethyl) diisobutylketimine, 2-(meth)acryloyloxyethylmethylcyanamide, cyanomethyl (meth)acrylate;

[0089] aryl(meth)acrylates, such as benzyl (meth)acrylate or phenyl(meth)acrylate, wherein each of the aryl groups can be unsubstituted orbe substituted at up to four positions;

[0090] carbonyl-containing (meth)acrylates, such as 2-carboxyethyl(meth)acrylate, N-(2-methacryloyloxyethyl)-2-pyrrolidinone,N-(3-methacryloyloxypropyl)-2-pyrrolidinone, carboxymethyl(meth)acrylate, N-methacryloylmorpholine, oxazolidinylethyl(meth)acrylate, N-(methacryloyloxy)formamide, acetonyl (meth)acrylate,N-methacryloyl-2-pyrrolidinone;

[0091] cycloalkyl (meth)acrylates, such as 3-vinylcyclohexyl(meth)acrylate, bornyl (meth)acrylate;

[0092] hydroxyalkyl (meth)acrylates such as 3-hydroxypropyl(meth)acrylate, 3,4-dihydroxybutyl (meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate;

[0093] glycol di(meth)acrylates, such as 1,4-butanediol (meth)acrylate;

[0094] methacrylates of ether alcohols, such as tetrahydrofurfuryl(meth)acrylate, vinyloxyethoxyethyl (meth)acrylate, methoxyethoxyethyl(meth)acrylate, 1-butoxypropyl (meth)acrylate,1-methyl-(2-vinyloxy)ethyl (meth)acrylate, cyclohexyloxymethyl(meth)acrylate, methoxymethoxyethyl (meth)acrylate, benzyloxymethyl(meth)acrylate, furfuryl (meth)acrylate, 2-butoxyethyl (meth)acrylate,2-ethoxyethoxymethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate,allyloxymethyl (meth)acrylate, 1-ethoxybutyl (meth)acrylate,methoxymethyl (meth)acrylate, 1-ethoxyethyl (meth)acrylate, ethoxymethyl(meth)acrylate;

[0095] methacrylates of halogenated alcohols, such as 2,3-dibromopropyl(meth)acrylate, 4-bromophenyl (meth)acrylate, 1,3-dichloro-2-propyl(meth)acrylate, 2-bromoethyl (meth)acrylate, 2-iodoethyl (meth)acrylate,chloromethyl (meth)acrylate;

[0096] oxiranyl (meth)acrylates, such as 10,11-epoxyundecyl(meth)acrylate, 2,3-epoxycyclohexyl (meth)acrylate, 2,3-epoxybutyl(meth)acrylate, 3,4-epoxybutyl (meth)acrylate, glycidyl (meth)acrylate;

[0097] methacrylates containing phosphorus, boron and/or silicon, suchas 2-(dibutylphosphono)ethyl (meth)acrylate, 2,3-butylene(meth)acryloylethyl borate 2-(dimethylphosphato)propyl (meth)acrylate, methyldiethoxy(meth)acryloyl ethoxy silane, 2(ethylenephosphito)propyl(meth)acrylate, dimethylphosphinomethyl (meth)acrylate,dimethylphosphonoethyl (meth)acrylate, diethyl(meth)acryloylphosphonate, diethylphosphatoethyl (meth)acrylate, dipropyl(meth)acryloyl phosphate;

[0098] sulfur-containing (meth)acrylates, such as ethylsulfinylethyl(meth)acrylate, 4-thiocyanatobutyl (meth)acrylate, ethylsulfonylethyl(meth)acrylate, thiocyanatomethyl (meth)acrylate, methylsulfinylmethyl(meth)acrylate, bis((meth)acryloyloxyethyl) sulfide;

[0099] tri(meth)acrylates, such as trimethyloylpropanetri(meth)acrylate; heterocyclic (meth)acrylates such as2-(1-imidazolyl)ethyl (meth)acrylate, 2-(4-morpholinyl)ethyl(meth)acrylate and 1-(2-methacryloyloxyethyl)-2-pyrrolidone.

[0100] Particularly preferred are (meth)acrylates derived from saturatedalcohols with 1 to 40 C atoms, preferably 6 to 24 C atoms, wherein thealcohol group may be straight-chain or branched.

[0101] The ester compounds with long-chain alcohol groups can beobtained, for example, by reaction of (meth)acrylates, fumarates,maleates and/or the corresponding acids with long-chain fatty alcohols,in which reaction a mixture of esters such as (meth)acrylates withalcohol groups of various chain lengths is generally obtained. Thesefatty alcohols include among others Oxo Alcohol® 7911, Oxo Alcohol® 7900and Oxo Alcohol® 1100 of Monsanto; Alphanol® 79 of ICI; Nafol® 1620,Alfol® 610 and Alfol® 810 of Condea; Epal® 610 and Epal® 810 of EthylCorporation; Linevol® 79, Linevol® 911 and Dobanol® 25L of Shell AG;Lial® 125 of Augusta, Milan; Dehydad® and Lorol® of Henkel KGaA as wellas Linopol® 7-11 and Acropol® 91 of Ugine Kuhlmann.

[0102] The ethylenically unsaturated monomers mentioned hereinabove canbe used individually or as mixtures. In preferred embodiments of theinventive process, at least 50 weight per cent of the monomers,preferably at least 60 weight per cent of the monomers, especiallypreferably more than 80 wt % of the monomers, relative to the totalweight of the ethylenically unsaturated monomers are (meth)acrylates. Itis also possible to vary the monomer composition during polymerization,in order to obtain well defined structures such as block copolymers.

[0103] Above and beyond this, monomer compositions are preferred whichcontain at least 60 weight per cent, especially preferably more than 80wt % of (meth)acrylates with alkyl or heteroalkyl chains containing atleast 6 carbon atoms, relative to the total weight of the ethylenicallyunsaturated monomers.

[0104] Besides the (meth)acrylates, also preferred are maleates andfumarates, which preferably also contain long-chain alcohol groups.

[0105] For example, a most particularly preferred monomer compositioncomprises the following ethylenically unsaturated monomers:

[0106] a) 60 to 100 wt %, especially 80 to 100 wt % of one or more(meth)acrylates of formula

[0107]  wherein R denotes hydrogen or methyl, R¹ denotes astraight-chain or branched alkyl group with 6 to 40 carbon atoms,preferably 6 to 24 carbon atoms, R² and R³ independently denote hydrogenor a group of the formula —COOR′, wherein R′ denotes hydrogen or astraight-chain or branched alkyl group with 6 to 40 carbon atoms,

[0108] b) 0 to 40 wt %, especially 0.5 to 20 wt % of one or more(meth)acrylates of formula (II)

[0109]  wherein R denotes hydrogen or methyl and R⁴ denotes astraight-chain or branched alkyl group with 1 to 5 carbon atoms,

[0110] c) 0 to 40 wt %, especially 0.5 to 20 wt % of one or more(meth)acrylates of formula (III)

[0111]  wherein R denotes hydrogen or methyl and R⁵ denotes an alkylgroup substituted with an OH group and containing 2 to 20, especially 2to 6 carbon atoms, or an alkoxylated group of formula (IV)

[0112]  wherein R⁶ and R⁷ independently denote hydrogen or methyl, R⁸denotes hydrogen or an alkyl group with 1 to 40 carbon atoms, and nstands for an integral number from 1 to 60,

[0113] d) 0 to 40 wt %, especially 0.5 to 20 wt % of one or more(meth)acrylates of formula (V)

[0114]  wherein R denotes hydrogen or methyl, X denotes oxygen or anamino group of formula —NH— or —NR¹⁰—, in which R¹⁰ stands for an alkylgroup with 1 to 40 carbon atoms, and R⁹ denotes a straight-chain orbranched alkyl group substituted with at least one —NR¹¹R¹²— group andcontaining 2 to 20, preferably 2 to 6 carbon atoms, wherein R¹¹ and R¹²independently stand for hydrogen, an alkyl group with 1 to 20,preferably 1 to 6 [carbon atoms], or in which R¹¹ and R¹² form a5-membered or 6-membered ring, which includes the nitrogen atom andpossibly one further nitrogen or oxygen atom, and which may also besubstituted with C₁ to C₆ alkyl, and

[0115] e) 0 to 40 wt %, especially 0.5 to 20 wt % of one or morecomonomers, wherein the value in wt % is in each case relative to thetotal weight of ethylenically unsaturated monomers.

[0116] Examples of these monomers have been cited in the foregoing.

[0117] Comonomers are ethylenically unsaturated monomers that can becopolymerized with the (meth)acrylates of formulas I, II, III and/or V.Besides styrene, preferred comonomers include in particular monomerswhich have dispersing effects, such as the heterocyclic vinyl compoundsmentioned hereinabove.

[0118] It must be pointed out at this place that halogen-containingmonomers can be incorporated into the polymer during the polymerization.Thus these monomers interfere with neither the polymerization nor thesubsequent halogen reduction, since only the living halogens areeliminated by the inventive reaction of the ATRP polymer with at leastone organic compound. Within the scope of the present invention,however, halogen-free monomers are preferred to those monomers whichcontain halogens.

[0119] The monomers mentioned hereinabove are polymerized by means ofinitiators that contain a transferable halogen. In general, theseinitiators can be described by the formula Y—(X)_(m), wherein Yrepresents the core molecule, which is assumed to form radicals, Xrepresents a transferable halogen and m denotes an integral number inthe range of 1 to 10, depending on the functionality of group Y. If m>1,the various transferable halogens X can have different meanings. If thefunctionality of the initiator is >2, star polymers are obtained.Preferred transferable halogens are Cl, Br and/or I. As mentionedhereinabove, it is assumed that group Y forms radicals that function asstarter molecules, in that this radical adds onto the ethylenicallyunsaturated monomers. Thus group Y preferably has substituents that canstabilize the radicals. Such substituents include among others —CN, —CORand —CO₂R, wherein R in each case denotes an alkyl or aryl group, oraryl and/or heteroaryl groups.

[0120] Alkyl groups are saturated or unsaturated, branched orstraight-chain hydrocarbon groups with 1 to 40 carbon atoms, such asmethyl, ethyl, propyl, butyl, pentyl, 2-methylbutyl, pentenyl,cyclohexyl, heptyl, 2-methylheptenyl, 3-methylheptyl, octyl, nonyl,3-ethylnonyl, decyl, undecyl, 4-propenylundecyl, dodecyl, tridecyl,tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl,eicosyl, cetyleicosyl, docosyl and/or eicosyltetratriacontyl.

[0121] Aryl groups are cyclic aromatic groups having 6 to 14 carbonatoms in the aromatic ring. These groups may be substituted. Examples ofsubstituents are straight-chain and branched alkyl groups with 1 to 6carbon atoms, such as methyl, ethyl, propyl, butyl, pentyl,2-methylbutyl or hexyl; cycloalkyl groups such as cyclopentyl andcyclohexyl; aromatic groups such as phenyl or naphthyl; amino groups,ether groups, ester groups as well as halides.

[0122] Examples of aromatic groups include phenyl, xylyl, toluyl,naphthyl or biphenylyl.

[0123] The expression “heteroaryl” denotes a heteroaromatic ring system,wherein at least one CH group is replaced by N or two neighboring CHgroups are replaced by S, O or NH, such as a thiophene, furan, pyrrole,thiazole, oxazole, pyridine, pyrimidine and benzo[a]furan group, whichmay also contain the substituents mentioned hereinabove. An initiatorthat is usable according to the invention can be any compound thatcontains one or more atoms or groups of atoms which can be transferredby a radical mechanism under the polymerization conditions.

[0124] Suitable initiators include those of the formulas:

R¹¹R¹²R¹³C—X

R¹¹C(═O)—X

R¹¹R¹²R¹³Si—X

R¹¹R¹²N—X

R¹¹N—X₂

(R¹¹)_(n)P(O)_(m)—X_(3-n)

(R¹¹O)_(n)P(O)_(m)—X_(3-n) and

(R¹¹)(R¹²O)P(O)_(m—X,)

[0125] wherein X is selected from the group comprising Cl, Br, I; andR¹¹, R¹² and R¹³ are chosen independently from the group comprisinghydrogen, halogens, alkyl groups with 1 to 20, preferably 1 to 10 andespecially preferably 1 to 6 carbon atoms, cycloalkyl groups with 3 to 8carbon atoms, R^(8*) ₃Si, C(═Y*)R^(5*), C(═Y*)NR^(6*)R^(7*), wherein Y*,R^(5*), R^(6*) and R^(7*) are as defined hereinabove, COCl, OH(preferably one of the groups R¹¹, R¹² and R¹³ is OH), CN, alkenyl oralkynyl groups with 2 to 20 carbon atoms, preferably 2 to 6 carbon atomsand especially preferably allyl or vinyl, oxiranyl, glycidyl, alkyleneor alkenylene groups with 2 to 6 carbon atoms, which are substitutedwith oxiranyl or glycidyl, aryl, heterocyclyl, aralkyl, aralkenyl(aryl-substituted alkenyl, wherein aryl is as defined hereinabove andalkenyl is vinyl substituted with one or two C₁ to C₆ alkyl groupsand/or halogen atoms, preferably with chlorine), alkyl groups with 1 to6 carbon atoms, in which one to all of the hydrogen atoms, preferablyone, are substituted by halogen (preferably fluorine or chlorine, if oneor more hydrogen atoms are replaced, and preferably fluorine, chlorineor bromine if one hydrogen atom is replaced), alkyl groups with 1 to 6carbon atoms, which are substituted with 1 to 3 substituents(preferably 1) chosen from the group comprising C₁ to C₄ alkoxy, aryl,heterocyclyl, C(═Y*)R^(5*) (wherein R^(5*) is as defined hereinabove),C(═Y*)NR^(6*)R^(7*) (wherein R^(6*) and R^(7*) are as definedhereinabove), oxiranyl and glycidyl (preferably not more than 2 of thegroups R¹¹, R¹² and R¹³ are hydrogen, and especially preferably at mostone of the groups R¹¹, R¹² and R¹³ is hydrogen); m=0 or 1; and n denotes0, 1 or 2.

[0126] The particularly preferred initiators include benzyl halides,such as p-chloromethylstyrene, α-dichloroxylene, α,α-dichloroxylene,α,α-dibromoxylene and hexakis(α-bromomethyl)benzene, benzyl chloride,benzyl bromide, 1-bromo-1-phenylethane and 1-chloro-1-phenylethane;carboxylic acid derivatives which are halogenated at the α-position,such as propyl 2-bromopropionate, methyl 2-chloropropionate, ethyl2-chloropropionate, methyl 2-bromopropionate, ethyl 2-bromoisobutyrate;tosyl halides such as p-toluenesulfonyl chloride; alkyl halides such astetrachloromethane, tribromomethane, 1-vinylethyl chloride, 1-vinylethylbromide; and halogen derivatives of phosphoric acid esters, such asdimethylphosphoric acid chloride.

[0127] The initiator is generally used in a concentration in the rangeof 10⁻⁴ mol/l to 3 mol/l, preferably in the range of 10⁻³ mol/l to 10⁻¹mol/l and especially preferably in the range of 5*10⁻² mol/l to 5*10⁻¹mol/l, although these values are not to be construed as limitative. Fromthe ratio of initiator to monomer there is obtained the molecular weightof the polymer, if the entire monomer is reacted. Preferably this ratioranges between 10⁻⁴ and 1 to between 0.5 and 1, especially preferablybetween 1*10⁻³ and 1 to between 5* 10⁻² and 1.

[0128] To carry out the polymerization there are used catalysts thatcomprise at least one transition metal. For this purpose there can beused any transition metal compound that can participate in a redox cyclewith the initiator or with the polymer chain, which contains atransferable group of atoms. In these cycles the transferable group ofatoms and the catalyst reversibly form a compound, wherein the oxidationnumber of the transition metal is raised or lowered. It is assumed thatradicals are liberated and trapped in this process, and so the radicalconcentration remains very low. It is also possible, however, that theinsertion of ethylenically unsaturated monomers into the Y—X orY(M)_(z)—X bond is made possible or facilitated by the addition of thetransition metal compound to the transferable group of atoms, where Yand X have the same meaning as given hereinabove and M denotes themonomers, while z indicates the degree of polymerization.

[0129] Preferred transition metals for this purpose are Cu, Fe, Co, Cr,Ne, Sm, Mn, Mo, Ag, Zn, Pd, Pt, Re, Rh, Ir, In, Yb and/or Ru, which canbe used in appropriate oxidation numbers. These metals can be usedindividually and also as mixtures. It is assumed that these metalscatalyze the redox cycles of the polymerization. In this connection, theCu⁺/Cu²⁺ or Fe²⁺/Fe³⁺ redox couple, for example, is effective.Accordingly, the metal compounds are added to the reaction mixture inthe form of halides such as chloride or bromide, as alkoxide, hydroxide,oxide, sulfate, phosphate, or hexafluorophosphate,trifluoromethanesulfate. The preferred metal compounds include Cu₂O,CuBr, CuCl, CuI, CuN₃, CuSCN, CuCN, CuNO₂, CuNO₃, CuBF₄, Cu(CH₃COO),Cu(CF₃COO), FeBr₂, RuBr₂, CrCl₂ and NiBr₂.

[0130] It is also possible, however, to use compounds with higheroxidation numbers, such as CuBr₂, CuCl₂, CuO, CrCl₃, Fe₂O₃ and FeBr₃. Inthese cases the reaction can be initiated by means of classical radicalsources, such as AIBN. In this case the transition metal compounds arereduced first of all, since they are reacted with the radicals generatedfrom the classical radical sources. Such a process is reverse ATRP, asdescribed by Wang and Matyjaszewski in Macromolecules (1995), Vol. 28,pp. 7572-7573.

[0131] Furthermore, the transition metals can be used for catalysis inthe form of metals of oxidation number zero, especially in a mixturewith the compounds mentioned hereinabove, as is described in, forexample, International Patent WO 98/40415. In these cases the reactionvelocity of the reaction can be increased. It is assumed that hereby theconcentration of catalytically active transition metal compound isincreased by using equal proportions of transition metals having highoxidation numbers and of metallic transition metal.

[0132] The preferred transition metals include metallic copper, whichcan be added to the reaction mixture in the form, for example, of coppersheet, copper wire, copper foil, copper shavings, copper gauze, copperbraid, copper textile and or copper powder as well as copper dust. Inthis connection, sources that can be readily separated once again fromthe polymer composition, such as copper sheet, copper wire, copper foiland copper braid are preferred over sources that are less easy toseparate, such as copper powder or copper dust.

[0133] In general, the molar ratio of transition metal to initiatorranges from 0.0001:1 to 10:1, preferably from 0.001:1 to 5:1 andespecially preferably from 0.01:1 to 2:1, although these values are notto be construed as limitative.

[0134] The polymerization takes place in the presence of ligands thatcan form a coordination compound with the metallic catalyst orcatalysts. Among other effects, these ligands function to increase thesolubility of the transition metal compound. A further importantfunction of the ligands is that the formation of stable organometalliccompounds is prevented. This is particularly important, since thesestable compounds would not polymerize under the chosen reactionconditions. It is further assumed that the ligands facilitateabstraction of the transferable group of atoms.

[0135] These ligands are known in themselves and are described in, forexample, International Patents WO 97/18247 and WO 98/40415. Thesecompounds generally contain one or more nitrogen, oxygen, phosphorusand/or sulfur atoms, via which the metal atom can be bound. Many ofthese ligands can be represented in general by the formula R¹⁶-Z-(R¹⁸-Z)_(m)-R¹⁷, wherein R¹⁶ and R¹⁷ independently denote H, C₁ toC₂₀ alkyl, aryl, heterocyclyl, which may or may not be substituted, andm represents an integral number ranging from 0 to 10. Such substituentsinclude among others alkoxy groups and alkylamino groups. R¹⁶ and R¹⁷may or may not form a saturated, unsaturated or heterocyclic ring. Zdenotes O, S, NH, NR¹⁹ or PR¹⁹, wherein R¹⁹ has the same meaning as R¹⁶.R¹⁸ independently denotes a divalent group with 1 to 40 C atoms,preferably 2 to 4 C atoms, which may be straight-chain, branched orcyclic, such as a methylene, ethylene, propylene or butylene group. Themeaning of alkyl and aryl has been explained hereinabove. Heterocyclylgroups are cyclic groups with 4 to 12 carbon atoms, in which one or moreof the CH₂ groups of the ring is or are replaced byheteroatom-containing groups, such as O, S, NH and/or NR, wherein thegroup R has the same meaning as R¹⁶.

[0136] A further group of suitable ligands can be represented by theformula

[0137] wherein R¹, R², R³ and R⁴ independently denote H, C₁, to C₂₀alkyl, aryl, heterocyclyl and/or heteroaryl groups, wherein the groupsR¹and R² or respectively R³ and R⁴ can together form a saturated orunsaturated ring.

[0138] Preferred ligands in this connection are chelate ligandscontaining N atoms.

[0139] The preferred ligands include among others triphenylphosphane,2,2-bipyridine, alkyl-2,2-bipyridine, such as4,4-di-(5-nonyl)-2,2-bipyridine, 4,4-di-(5-heptyl)-2,2-bipyridine,tris(2-aminoethyl)amine (TREN),N,N,N′,N′,N″-pentamethyldiethylenetriamine,1,1,4,7,10,10-hexamethyltriethylenetetramine and/ortetramethylethylenediamine. Further preferred ligands are described in,for example, International Patent WO 97/47661. The ligands can be usedindividually or as a mixture.

[0140] These ligands can form coordination compounds in situ with themetal compounds, or they can be synthesized first as coordinationcompounds and then added to the reaction mixture.

[0141] The ratio of ligand to transition metal depends on the dentatenumber of the ligand and on the coordination number of the transitionmetal. In general, the molar ratio ranges from 100:1 to 0.1:1,preferably from 6:1 to 0.1:1 and especially preferably from 3:1 to0.5:1, although these values are not to be construed as limitative.

[0142] The monomers, transition metal catalysts, ligands and initiatorsare selected as a function of the desired polymer solution. It isassumed that a high rate constant of the reaction between the complex oftransition metal with ligand and the transferable group of atoms isessential for a narrow molecular weight distribution. If the rateconstant of this reaction is too low, the concentration of radicalsbecomes too high, and so the typical termination reactions responsiblefor a broad molecular weight distribution occur. The exchange ratedepends on, for example, the transferable group of atoms, the transitionmetal, the ligands and the anion of the transition metal compound. Theperson skilled in the art will find useful guides to selection of thesecomponents in, for example, International Patent WO 98/40415.

[0143] The polymerization can be performed at normal, reduced orabove-atmospheric pressure. The polymerization temperature also is notcritical. In general, however, it ranges from −20° to 200° C.,preferably from 0° to 130° C. and especially preferably from 60° to 120°C., although these values are not to be construed as limitative.

[0144] By means of the present process, polymers with a predeterminedarchitecture can be obtained in simple manner. These possibilitiesresult from the “living” character of the polymerization process. Suchstructures include among others block copolymers, gradient copolymers,star polymers, highly branched polymers, polymers with reactive terminalgroups and graft copolymers.

[0145] It may be of special interest for the inventive process tosynthesize, in the polymer composition, a copolymer with non-statisticalstructure, preferably a two-block, three-block or gradient polymer.

[0146] The polymers synthesized within the scope of the inventiongenerally have a molecular weight ranging from 1,000 to 1,000,000 g/mol,preferably from 5*10³ to 500*10³ g/mol and especially preferably from10*10³ to 300*10³ g/mol, although these values are not to be construedas limitative. These values refer to the weight-average molecular weightof the polydisperse polymers in the composition.

[0147] The special advantage of ATRP compared with conventional radicalpolymerization processes is that polymers with a narrow molecular weightdistribution can be synthesized. While the following values are not tobe construed as limitative, polymers obtained by the inventive processhave a polydispersity, expressed by M_(w)/M_(n), ranging from 1 to 12,preferably from 1 to 4.5, especially preferably from 1 to 3 and mostparticularly preferably from 1.05 to 2.

[0148] The polymerization as a partial step of the present synthesisprocess can be performed with or without solvent. It is characteristicof the process that reduction of the halogen content of the polymerspresent in the composition takes place in a nonpolar solvent by reactionwith an organic nitrogen compound.

[0149] Accordingly, an appropriate solvent can be added before thereaction with an organic nitrogen compound or else after thepolymerization, or else the polymerization takes place in the presenceof a nonpolar solvent. The term solvent is to be understood broadly inthe present connection. For example, unreacted monomers that remain inthe composition after the polymerization can also function as solvents.

[0150] As a measure for the polarity of the solvent there can be usedthe dielectric constant, which is preferably ≦4, expediently ≦3 and mostparticularly preferably ≦2.5. This value is determined at 20° C., andthe person skilled in the art can find useful guidelines on themeasurement in Ullmanns Encyclopedia of Industrial Chemistry, 1966,Volume II/2, pages 455 to 479.

[0151] According to an interesting viewpoint of the inventive process,the catalyst can be separated by a solid-liquid separation method afterthe polymerization. Chromatography, centrifugation and filtration areexamples of techniques for this purpose.

[0152] Preferably the catalyst is removed by filtration. For thispurpose the oxidation number of the transition metal is raised followingpolymerization. Oxidation of the transition metal leads to decreasedcatalyst solubility, to a degree depending on the choice of ligand orligands, and so the transition metal can be separated by filtration inthe presence of a solvent, especially a mineral oil, whose dielectricconstant is ≦4, preferably ≦3 and especially preferably ≦2.5.

[0153] Oxidation of the transition metal can be achieved with knownoxidizing agents such as oxygen, H₂O₂ or ozone. Preferably the catalystwill be oxidized with atmospheric oxygen. Complete oxidation of thetransition metal or of the transition metal compound is not necessary.In many cases it is sufficient to bring the composition into contactwith atmospheric oxygen for a few minutes in order to ensure sufficientprecipitation of the transition metal compound.

[0154] Filtration is known in itself and is described in, for example,Ullmann's Encyclopedia of Industrial Chemistry, Fifth Edition, key word“Filtration”. Preferably the composition is purified at a pressuredifference ranging from 0.1 to 50 bar, preferably 1 to 10 bar andespecially preferably 1.5 to 2.5 bar with a filter having a sieve sizeranging from 0.01 μm to 1 mm, preferably 1 μm to 100 μm and especiallypreferably 10 μm to 100 μm. These values are to be considered asreference points, since the purification also depends on the viscosityof the solvent and on the particle size of the precipitate.

[0155] The filtration is performed in a temperature range similar tothat of polymerization, the upper range being dependent on the stabilityof the polymers. The lower limit is determined by the viscosity of thesolution.

[0156] The polymer composition synthesized in this way can be usedwithout further purification as, for example, an additive in lubricatingoils. Furthermore, the polymer can be isolated from the composition. Forthis purpose the polymers can be separated from the composition byprecipitation.

[0157] The invention will be explained in more detail hereinafter byexamples and comparison examples, although the invention is not to beconstrued as limited to these examples.

[0158] I) Particulars of Starting Materials and Methods:

[0159] I.1) Starting Materials

[0160] The alkyl methacrylate mixture of C₁₂ to C₁₈ alcohols used,obtainable by transesterification of MMA with Lial 125 of Augusta® ofMilan, was weighed out, assuming a purity of 98%. Cu₂O (particle size 5μm), EBiB (ethyl 2-bromoisobutyrate), PMDETA(pentamethyldiethylenetriamine), DETA (diethylenetriamine) TMEDA(tetramethylethylenediamine) as well as Primine 81R (NH₂—C₁₃H₂₇) wereobtained from Aldrich and, in common with MMA (methyl methacrylate;Rohm), were weighed out as assuming a purity of 100%. The mineral oilused was an oil of the Shell Co. (SM 920; composition: 0.84% n-alkaneswith about 18 to 31 C atoms, 5.16% slightly branched alkanes with 18 to31 atoms, 8.8% aromatics with 14 to 32 C atoms, 71.4% isoalkanes andcycloalkanes with 20 to 32 C atoms, 0.6% polar compounds, 13.2% loss).Tonsil L80 FF of Südchemie was used to prepare the Tonsil column.

[0161] I.2 Analysis Methods

[0162] The samples were worked up by purification over an Al₂O₃/Tonsil(2:1) column. Hereby all catalyst residues as well as precipitates wereseparated. The samples were then digested according to Schöniger, afterwhich the Br content was determined argentometrically.

[0163] II. Execution of the Examples and Comparison Examples

EXAMPLE I

[0164] 41.6 g (0.416 mol) of MMA and 278.4 g of an alkyl methacrylatemixture of C₁₂ to C₁₈ alcohols in 80 g of mineral oil were placed in a750 ml four-necked flask, through which nitrogen was flowing, equippedwith sickle-shaped stirrer, reflux condenser and internal thermometer,and were inerted by addition of dry ice.

[0165] 0.55 g (0.1 mol) of PMDETA followed by 7.34 g (0.05 mol) offinely powdered Cu₂O was added, after which the reaction mixture washeated from room temperature to 90° C. As soon as the solution hadreached the desired temperature, 6.24 g (1 mol) of Ebib was added. Thetemperature was then raised to 95° C. After 6 hours, 8.25 g (1.5 mol) ofPMDETA was added, and the temperature was then raised to 110° C.

[0166] After 24 hours a sample was taken and then cooled, worked up andanalyzed.

[0167] The obtained sample had a polydispersity of 1.32 as well as anM_(n) value of 12,900 g/mol, as determined by means of GPC. One gram ofthe purified sample contained 8 μg of copper and 38 μg of bromine.

EXAMPLE 2

[0168] The polymerization was carried out as in Example 1, except that16.5 g (3 mol) of PMDETA was added after 6 hours and then thetemperature was raised to 110° C.

[0169] After 24 hours a sample was taken and then cooled, worked up andanalyzed.

[0170] The obtained sample had a polydispersity of 1.27 as well as anM_(n) value of 13,600 g/mol, as determined by means of GPC. One gram ofthe purified sample contained 12 μg of copper and less than 50 μg ofbromine.

EXAMPLE 3

[0171] The polymerization was carried out as in Example 1, except that8.25 g (1.5 mol) of PMDETA was added after 6 hours and then thetemperature was raised to 130° C.

[0172] After 24 hours a sample was taken and then cooled, worked up andanalyzed.

[0173] The obtained sample had a polydispersity of 1.31 as well as anM_(n) value of 13,100 g/mol, as determined by means of GPC. One gram ofthe purified sample contained 11 μg of copper and 95 μg of bromine.

[0174] COMPARISON EXAMPLE 1

[0175] The polymerization was carried out as in Example 1, except that,after 6 hours, the temperature was raised to 110° C. without addition ofPMDETA.

[0176] After 24 hours the solution was cooled, worked up and analyzed.One gram of the purified solution contained 3875 μg of bromine, whilethe polymer had a polydispersity of 1.26 as well as an M_(n) value of13,000 g/mol, as determined by means of GPC.

EXAMPLE 4

[0177] The polymerization was carried out as in Example 1, except that2.2 g (0.4 mol) of PMDETA and 66.06 g (0.45 mol) of Cu₂O were addedafter 6 hours and then the temperature was raised to 110° C. After 24hours the solution was cooled, worked up and analyzed. One gram of thepurified solution contained 5 μg of copper and 469 μg of bromine, whilethe polymer had a polydispersity of 1.30 as well as an M_(n) value of14,100 g/mol, as determined by means of GPC.

EXAMPLE 5

[0178] The polymerization was carried out as in Example 1, except that4.95 g (0.9 mol) of PMDETA and 139.46 g (0.45 mol) of Cu₂O were addedafter 6 hours and then the temperature was raised to 110° C.

[0179] After 24 hours the solution was cooled, worked up and analyzed.One gram of the purified solution contained 800 μg of copper and 943 μgof bromine, while the polymer had a polydispersity of 1.32 as well as anM_(n) value of 14,600 g/mol, as determined by means of GPC.

EXAMPLE 6

[0180] The polymerization was carried out as in Example 1, except that4.94 g (1.5 mol) of DETA was added after 6 hours and then thetemperature was raised to 110° C.

[0181] After 24 hours the solution was cooled, worked up and analyzed.One gram of the purified solution contained 529 μg of bromine.

EXAMPLE 7

[0182] The polymerization was carried out as in Example 1, except that28.8 g (4.5 mol) of Primine 81R was added after 6 hours and then thetemperature was raised to 110° C.

[0183] After 24 hours the solution was cooled, worked up and analyzed.One gram of the purified solution contained 848 μg of bromine.

EXAMPLE 8

[0184] The polymerization was carried out as in Example 1, except that8.4 g (2.26 mol) of TMEDA was added after 6 hours and then thetemperature was raised to 110° C.

[0185] After 24 hours the solution was cooled, worked up and analyzed.One gram of the purified solution contained 199 μg of bromine.

EXAMPLE 9

[0186] The polymerization was carried out as in Example 1, except that,once 8.25 g (1.5 mol) of PMDETA had been added after 6 hours, thetemperature was maintained at 95° C.

[0187] After 24 hours the solution was cooled, worked up and analyzed.One gram of the purified solution contained 89 μg of bromine.

COMPARISON EXAMPLE 2

[0188] The polymerization was carried out as in Example 1, except that8.4 g (1.5 mol) of α-methylstyrene was added after 6 hours. Thetemperature was maintained at 95° C.

[0189] After 24 hours the solution was cooled, worked up and analyzed.One gram of the purified solution contained 4625 μg of bromine.

1. A process for synthesis of polymer compositions with reduced livinghalogen content, wherein ethylenically unsaturated monomers arepolymerized by means of initiators containing a transferable halogen andof one or more catalysts comprising at least one transition metal in thepresence of ligands which can form a coordination compound with themetal catalyst or catalysts and, after the polymerization, the livinghalogen atoms present in the polymer are at least partly eliminated,characterized in that, after the polymerization, the polymer compositionis reacted with at least one organic nitrogen compound in the presenceof a nonpolar solvent.
 2. A process according to claim 1, characterizedin that the nonpolar solvent is used in a proportion of 5 to 95 wt %relative to the total weight.
 3. A process according to claim 1 or 2,characterized in that a mineral oil and/or a synthetic oil is used asthe nonpolar solvent.
 4. A process according to claim 3, characterizedin that there is used a mineral oil which contains 0.5 to 30 wt % ofaromatic constituents, 15 to 40 wt % of naphthenic constituents, 35 to80 wt % of paraffinic constituents, up to 3 wt % of n-alkanes and 0.05to 5 wt % of polar compounds, each relative to the total weight of themineral oil.
 5. A process according to one or more of the precedingclaims, characterized in that one or more heterocyclic aromatic nitrogencompounds is used as the organic nitrogen compound.
 6. A processaccording to claim 5, characterized in that a compound which containsone or more pyridine groups is used as the organic nitrogen compound. 7.A process according to one or more of the preceding claims,characterized in that one or more aliphatic nitrogen compounds is usedas the organic nitrogen compound.
 8. A process according to claim 7,characterized in that a compound which contains one or more amine groupsis used as the organic nitrogen compound.
 9. A process according toclaim 8, characterized in that an amine compound in which at least onemethyl group is bound to its nitrogen atom, such ashexamethyltriethylenetetramine, PMDETA or TMEDA, is used as the organicnitrogen compound.
 10. A process according to one or more of thepreceding claims, characterized in that the organic nitrogen compound isused in excess relative to the halogen-containing initiator used for thepolymerization.
 11. A process according to claim 10, characterized inthat the molar ratio of organic nitrogen compound to living halogenranges from 0.5:1 to 10:1.
 12. A process according to one or more of thepreceding claims, characterized in that, after the polymerization, thepolymer composition is reacted at a temperature in the range of 20 to2000° C.
 13. A process according to one or more of the preceding claims,characterized in that, after the polymerization, the polymer compositionis reacted with the organic nitrogen compound for at least 1 hour.
 14. Aprocess according to one or more of the preceding claims, characterizedin that there are polymerized ethylenically unsaturated monomers whichcontain 50 to 100 wt %, relative to the total weight of theethylenically unsaturated monomers, of one or more ethylenicallyunsaturated ester compounds of formula (I)

wherein R denotes hydrogen or methyl, R¹ denotes a straight-chain orbranched alkyl group with 8 to 40, preferably 10 to 40 carbon atoms, R²and R³ independently denote hydrogen or a group of the formula —COOR′,wherein R′ denotes hydrogen or a straight-chain or branched alkyl groupwith 8 to 40, preferably 10 to 40 carbon atoms.
 15. A process accordingto one or more of the preceding claims, characterized in that there ispolymerized a monomer composition containing at least 50 wt % of one ormore (meth)acrylates of formula (II)

wherein R denotes hydrogen or methyl and R¹ denotes a straight-chain orbranched alkyl group with 8 to 40, preferably 10 to 40 carbon atoms. 16.A process according to one or more of the preceding claims,characterized in that there is polymerized a monomer compositioncontaining a) 60 to 100 wt % of one or more ethylenically unsaturatedester compounds of formula (I)

wherein R denotes hydrogen or methyl, R¹ denotes a straight-chain orbranched alkyl group with 8 to 40, preferably 10 to 40 carbon atoms, R²and R³ independently denote hydrogen or a group of the formula —COOR′,wherein R′ denotes hydrogen or a straight-chain or branched alkyl groupwith 8 to 40, preferably 10 to 40 carbon atoms, b) 0 to 40 wt % of oneor more (meth)acrylates of formula (III)

wherein R denotes hydrogen or methyl and R⁴ denotes a straight-chain orbranched alkyl group with 1 to 7 carbon atoms, c) 0 to 40 wt % of one ormore (meth)acrylates of formula (IV)

wherein R denotes hydrogen or methyl and R⁵ denotes an alkyl group,substituted with an OH group, with 2 to 20 carbon atoms, or anethoxylated group of formula (V)

wherein R⁶ and R⁷ independently stand for hydrogen or methyl, R⁸ standsfor hydrogen or an alkyl group with 1 to 40 carbon atoms, and n standsfor an integral number from 1 to 60, d) 0 to 40 wt % of one or more(meth)acrylates of formula (VI)

wherein R denotes hydrogen or methyl, X denotes oxygen or an amino groupof formula —NH— or —NR¹⁰—, wherein R¹⁰ stands for an alkyl group with 1to 40 carbon atoms, and R⁹ denotes a straight-chain or branched alkylgroup, substituted by at least one —NR¹¹R¹² group, with 2 to 20,preferably 2 to 6 carbon atoms, wherein R¹¹ and R¹² independently of oneanother stand for hydrogen, an alkyl group with 1 to 20, preferably 1 to6 [carbon atoms], or wherein R¹¹ and R¹² form a 5-membered or 6-memberedring, which includes the nitrogen atom and possibly one further nitrogenor oxygen atom, and which may or may not be substituted with C₁ to C₆alkyl, and e) 0 to 40 wt % of one or more comonomers, wherein the wt %value in each case is relative to the total weight of ethylenicallyunsaturated monomers.
 17. A process according to claim 16, characterizedin that styrene, (meth)acrylate derivatives and/or dispersing monomersare used as comonomers.
 18. A process according to one or more of thepreceding claims, characterized in that metallic copper, Cu₂O, CuBr,CuCl, CuI, CuN₃, CuSCN, CuCN, CuNO₂, CuNO₃, CuBF₄, Cu(CH₃COO) orCu(CF₃COO) are used as the catalyst.
 19. A process according to one ormore of the preceding claims, characterized in that at least one chelateligand containing N atoms is used.
 20. A process according to one ormore of the preceding claims, characterized in that an initiatorcontaining Cl, Br and/or I as the transferable halogen is used.
 21. Aprocess according to one or more of the preceding claims, characterizedin that the catalyst and the halogen compound eliminated from thepolymer are separated by solid-liquid separation.
 22. Polymercompositions with reduced living halogen content, obtainable accordingto one or more of processes 1 to 21, characterized in that the livinghalogen content of the polymer compositions is ≦1000 ppm.
 23. Polymercompositions according to claim 22, characterized in that the halogencontent of the polymer compositions is ≦100 ppm.
 24. The use of apolymer composition obtained by a process according to one or more ofclaims from 1 to 21 as an additive to lubricating oils.